textproduct: Albany

WHAT HAS CHANGED

The previous forecast remains largely on track, so no significant changes were made with this update.

KEY MESSAGES

1) Dangerous heat and humidity return in greater magnitude and on a more widespread scale today than yesterday, increasing the risk for heat-related illness.

2) There is potential for additional isolated to scattered strong to severe thunderstorms across eastern New York and western New England today with the primary threat of strong to damaging wind gusts.

3) There is potential for another round of showers and thunderstorms, some of which could become severe, on Sunday.

DISCUSSION

KEY MESSAGE 1...

Dangerous heat and humidity return once again today, though to a greater spatial extent and magnitude than yesterday. A narrow, localized ridge preceding an incoming cold front and upper-level trough will trigger an increase in geopotential height that's sufficient to allow 850mb temperatures to surge to +17C to +19C (2 STDEVs above normal). This, paired with limited cloud coverage as well as mesoscale enhancement to heating within valley areas through downsloping of westerly to southwesterly winds, will translate to surface highs reaching the 80s to 90s across the region. These values, paired with dewpoints in the mid/upper 60s to low 70s, will make for oppressive conditions across a large portion of our area. Therefore, a Heat Advisory remains in effect from noon to 8 PM this evening. Caution is advised to all populations, but especially those who may be susceptible to heat- related illness and work outdoors for prolonged periods of time. Be sure to drink plenty of water and limit the duration of exposure to the heat by planning frequent breaks within a cooled location.

KEY MESSAGE 2...

Latest RGB and water vapor imagery shows a decaying mesoscale convective system oriented from northeast to southwest from the Ohio River Valley through the southern Mississippi River Valley. Directly upstream, a negatively tilting trough is digging into the Upper Midwest with a deepening surface cyclone straddling the international border over Lake Huron extending its attendant cold front to the south and west along the trailing edge of the weakening convection. It's these features that will ultimately serve as the forcing mechanisms for the anticipated convection across eastern New York and western New England this afternoon into this evening.

The magnitude of heat and humidity that will be in place across the region today will easily provide a requisite unstable environment to promote severe thunderstorm potential this afternoon into this evening. In fact, MLCAPE values across eastern New York and western New England will rise to about 500-1500 J/kg, particularly within valley areas where temperatures and dewpoints will be greatest. 0-6km shear vectors with values ranging from about 15-30kt and a perpendicular component to the incoming cold front suggest a discrete storm mode with the potential for some storms to reach severe strength through the development of sufficiently organized updrafts.

Latest guidance indicates that the cold front will make its passage later this afternoon through this evening, driving the alignment of the best low-level and upper-level forcing as diffluent flow increases aloft with the encroachment of the axis of the upper trough. This timing will also place us in an area of fairly strong PVA and subsequent height falls which will only act to enhance vertical ascent further. Increasing flow aloft in tandem with marginally straight hodographs and a very moist environment that will support precipitation loading will drive strong to damaging wind gusts as our primary hazard for the day. To add confidence to this thought, latest HiRes guidance seems to be picking up on the potential for remnant outflow from the aforementioned decaying convection to race into our CWA through this afternoon and alter the environment slightly. Previously, the guidance was indicating marginally steep mid- level lapse rates that were maximized around 5.5-6C/km. However, 06z guidance is now highlighting an area of steeper 700-500mb lapse rates that reach 6.5C/km which suggests entrainment effects of this drier, cooler remnant flow. Steeper lapse rates resulting from this outflow could act to enhance the damaging wind gust potential through strong dynamic cooling while also increasing the secondary hazard potential of hail.

The Storm Prediction Center has kept our entire CWA within a Slight Risk (Level 2 of 5) for severe weather for today, suggesting isolated to scattered coverage of severe storms. While there remains uncertainty in the exact coverage at this time, the greatest probability of damaging wind gusts lies within areas south of I-90 including portions of the Eastern Catskills and Mid-Hudson Valley. Here, a 30-44% probability of severe wind gusts exists within 25 miles of any point location. Elsewhere, a 15-29% probability stands. And while the exact timing of severe storms remains somewhat uncertain, the window of time for the greatest threat of severe weather spans about 2 PM through 8 PM.

KEY MESSAGE 3...

One day of respite from the intense heat/humidity and severe weather potential comes Saturday as high pressure reinforces dry conditions regionwide and high temperatures span the 70s to upper 80s. While those values may not sound like much of a reprieve from the heat, they will certainly not feel any worse given dewpoints largely in the 50s. Sunday's temperatures will be fairly similar, though a few degrees warmer, with highs in the mid/upper 70s to low 90s. However, Sunday will once again present the opportunity for at least showers and non-severe thunderstorms. But, depending on the time of an impending cold front, highly unstable conditions and bulk shear around 30-40 kt certainly suggests the potential for another round of severe thunderstorms. We will continue to monitor trends closely and begin messaging any hazards accordingly as confidence increases.

AVIATION /08Z FRIDAY THROUGH TUESDAY/

Through 06z Saturday...Moist/humid environment in place across the region, but thick mid level cloud deck in place from KALB to KPSF and KPOU, which should be overhead much of the night, will likely limit fog development. Clouds are dissipating at KGFL though, so there is a higher confidence in at least occasional fog and IFR/LIFR conditions there from around 07z-11z. There may be enough breaks towards 08z or 09z for some fog especially at KPSF, so will mention a TEMPO for IFR/LIFR there for a few hours with MVFR at KPOU. Any fog should end by 11z. Additional mid level clouds are expected to develop shortly after sunrise, but will likely be at VFR levels. Scattered TSRA are expected to develop after 18z today associated with a cold front. Will mention PROB30 at all TAF sites, with potential for brief IFR conditions and strong/gusty winds. Outside of TSRA activity, winds will initially be variable less than 5 kt, becoming westerly and increasing to 5-11 kt this afternoon.

Outlook...

Friday Night: Low Operational Impact. NO SIG WX. Saturday: No Operational Impact. NO SIG WX. Saturday Night: No Operational Impact. NO SIG WX. Sunday: Moderate Operational Impact. Breezy. Chance of SHRA...TSRA. Sunday Night: High Operational Impact. Definite SHRA...TSRA. Monday: No Operational Impact. NO SIG WX. Monday Night: No Operational Impact. NO SIG WX. Tuesday: Low Operational Impact. Slight Chance of SHRA...TSRA.

CLIMATE

Record High Temperatures(Year Set):

Thursday June 11: Albany: 94(1947) Glens Falls: 94(1894) Poughkeepsie: 95(1973)

Friday June 12: Albany: 95(2017) Glens Falls: 92(2017) Poughkeepsie: 95(1933)

ALY WATCHES/WARNINGS/ADVISORIES

CT...Heat Advisory from noon today to 8 PM EDT this evening for CTZ001-013. NY...Heat Advisory from noon today to 8 PM EDT this evening for NYZ038>041-043-047>053-059>061-063>066-082>084. MA...Heat Advisory from noon today to 8 PM EDT this evening for MAZ025. VT...Heat Advisory from noon today to 8 PM EDT this evening for VTZ013-015.